Encyclopedia of Health and Medicine

196 The Pulmonary System
Regular physical activity and avoiding cigarette
smoke are crucial to preserve remaining lung
function.
See also ATELECTASIS; AUSCULTATION.
bronchitis INFLAMMATION of the bronchi, the airways
that branch from the TRACHEA into the LUNGS.
Bronchitis may be viral, bacterial, or the result of
irritation such as cigarette smoking or exposure to
environmental pollutants. It may also occur as an
acute condition that comes on suddenly, runs its
course, and heals without lasting damage or persistently
recur as a chronic condition.
Acute bronchitis Acute infectious bronchitis is
especially common during the “cold and flu” season,
when it typically follows a viral INFECTION of
the upper respiratory tract. Numerous viruses may
be responsible, including ADENOVIRUS, coronaviruses,
INFLUENZA viruses, and rhinoviruses.
Acute viral bronchitis generally runs its course
over a period of five to seven days, during which
the person feels and appears ill. A residual COUGH
may persist for several weeks after the infection
subsides.
Acute irritative bronchitis develops in response
to inhaled irritants such as fumes, dust, and
smoke (cigarette as well as environmental). Symptoms
may be difficult to distinguish from those of
ASTHMA, particularly in people who do not have a
diagnosis of asthma or who have infrequent
asthma attacks. The inhaled substance irritates the
lining of the bronchi, causing localized inflammation.
Most often, the inflammation and resulting
bronchitis subsides over the course of a few days.
Chronic bronchitis Repeated exposure to irritants
such as cigarette smoke, occupational chemicals,
and environmental pollutants may cause
persistent or recurrent bronchial inflammation. By
far the most common culprit is cigarette smoking
or environmental cigarette smoke exposure (second-hand
smoking). The hallmark symptom is
persistent, productive cough that continues for
three months or longer. Over time, chronic bronchitis
may evolve into CHRONIC OBSTRUCTIVE PUL-
MONARY DISEASE (COPD) or BRONCHIECTASIS, two
conditions in which damage to the bronchi is
extensive and permanent. People who have
chronic bronchitis are more vulnerable to bacterial
infections such as PNEUMONIA, as well as to complications
such as ATELECTASIS (collapse of a bronchial
segment).
Symptoms and Diagnostic Path
The symptoms of acute bronchitis include FEVER,
productive cough, sore THROAT, and chest discomfort
or PAIN, especially when taking a deep breath.
SPUTUM that is thick, yellowish green, and foulsmelling
suggests bacterial infection. Red or brown
streaks in the sputum indicate bleeding, which
may be from the irritation of coughing or signal a
different diagnosis. The diagnostic path includes
AUSCULTATION to listen to BREATH SOUNDS, which are
typically normal. The doctor may request a chest
X-RAY to rule out other causes of the symptoms.
The doctor may also collect a sputum sample for
culture if there is any suspicion the infection could
be bacterial.
The primary symptoms of chronic bronchitis
are productive cough and DYSPNEA (shortness of
breath). Physical exertion tends to exacerbate
both. The diagnostic path begins with auscultation,
which may reveal abnormalities of breath
sounds depending on whether there is damage to
the bronchial structures. Chest X-ray may show
areas of inflammation as well as atelectasis or
bronchiectasis if either is present. The doctor is
likely to conduct further diagnostic procedures to
rule out other conditions that could cause similar
symptoms, such as asthma or, especially in smokers,
LUNG CANCER.
Treatment Options and Outlook
Treatment for acute viral bronchitis is primarily
supportive and targets symptom relief. The doctor
may recommend a cough suppressant or an OVER-
THE-COUNTER (OTC) DRUG such as acetaminophen
to relieve fever and discomfort. It is important to
drink lots of fluids to maintain HYDRATION and to
thin bronchial secretions. When fever persists or
recurs after acute infectious bronchitis, the likelihood
of bacterial infection is high in which case
treatment with ANTIBIOTIC MEDICATIONS becomes
necessary. Antibiotics are not helpful for viral
bronchitis, however. The doctor may prescribe an
inhaled corticosteroid medication to suppress the
inflammatory response in acute irritative bronchitis.
Bronchodilators may also help if the bronchitis
causes bronchospasm and wheezing.